Andy Burnham has just won what might be the most consequential byelection in British political history. His win clears the way for him to enter parliament as a Labour MP and challenge Sir Keir Starmer to become prime minister of the United Kingdom.
But this win isn’t just about filling a constituency vacancy with another MP to populate the lobbies at Westminster. Nor is it even only about a challenge to Starmer’s leadership - although that is now on the cards.
